Comments on: D-Wave’s Quantum Computers are the Real Deal http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/ Chinese, Linguistics, Science, Cultural Observations and whatever else I feel like writing about Fri, 22 Aug 2008 02:59:02 +0000 http://wordpress.org/?v=2.6 By: Mark http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-140010 Mark Sun, 11 May 2008 19:58:54 +0000 http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-140010 I have become somewhat concerned by the D-Wave blog's frequent suggestions that a quantum computer would revolutionize the calculation of NP-complete problems. From what I understand, q-bits allow factorization (e.g. RSA breaking) in polynomial time, but NP-complete problems are a completely different beast. Most likely a quantum computer would only reduce the time to square root of that required by a conventional one. For a 1000 point traveling salesman problem, the a quantum computer would require 2<sup>500</sup> steps, rather than 2<sup>1000</sup>. In other words, NP-complete problems would still be essentially unsolvable. http://www.scottaaronson.com/writings/limitsqc-draft.pdf I'm still convinced that D-Wave has a true break-through, but these kinds of unsubstantiated claims are a pretty big red flag. I have become somewhat concerned by the D-Wave blog’s frequent suggestions that a quantum computer would revolutionize the calculation of NP-complete problems. From what I understand, q-bits allow factorization (e.g. RSA breaking) in polynomial time, but NP-complete problems are a completely different beast. Most likely a quantum computer would only reduce the time to square root of that required by a conventional one. For a 1000 point traveling salesman problem, the a quantum computer would require 2500 steps, rather than 21000. In other words, NP-complete problems would still be essentially unsolvable.

http://www.scottaaronson.com/writings/limitsqc-draft.pdf

I’m still convinced that D-Wave has a true break-through, but these kinds of unsubstantiated claims are a pretty big red flag.

]]> By: todd http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-114101 todd Thu, 27 Dec 2007 20:15:21 +0000 http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-114101 I have a bunch of data and photos that I encrypted with DH/DSS 1024/2048 and I forgot my passphrase. So I'm rooting for DWave so I can get my stuff back! :-) I bet they'll have a 1024 qbit prototype in a less than 3 years! I have a bunch of data and photos that I encrypted with
DH/DSS 1024/2048 and I forgot my passphrase. So I’m
rooting for DWave so I can get my stuff back! :-)
I bet they’ll have a 1024 qbit prototype in a less than
3 years!

]]> By: trevelyan http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-104207 trevelyan Wed, 14 Nov 2007 12:53:43 +0000 http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-104207 I was under the impression (from reading some of Schneier's stuff) that quantum computing made it expontentially easier to solve certain types of factoring problems (ie. breaking RSA), but would not instantly obliviate other sorts of encryption algorithms. The potential for these devices for pattern recognition and neural networks is very cool. I was under the impression (from reading some of Schneier’s stuff) that quantum computing made it expontentially easier to solve certain types of factoring problems (ie. breaking RSA), but would not instantly obliviate other sorts of encryption algorithms.

The potential for these devices for pattern recognition and neural networks is very cool.

]]> By: Mark http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-104072 Mark Wed, 14 Nov 2007 05:57:12 +0000 http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-104072 512-qbits can do quite a bit in terms of encryption breaking and 1024-qbits would far, far outstrip any other computer on the planet. Dr. Rose said on his blog that they should be able to factor RSA-704 once they hit 512-qbits. Read the 12th and 13th comments to the post on his blog that I cited for the picture of the chip. 512-qbits can do quite a bit in terms of encryption breaking and 1024-qbits would far, far outstrip any other computer on the planet.

Dr. Rose said on his blog that they should be able to factor RSA-704 once they hit 512-qbits. Read the 12th and 13th comments to the post on his blog that I cited for the picture of the chip.

]]> By: sanktnelson http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-103916 sanktnelson Wed, 14 Nov 2007 00:16:42 +0000 http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-103916 Actually, D-wave's Geordie Rose has said repeatedly that the type of Quantum computer that they're currently building is not suitable to break encryption. Although their adiabatic approach can be extended to be computationally equivalent to the gate-model approach, this seems to be not planned at the moment. Actually, D-wave’s Geordie Rose has said repeatedly that the type of Quantum computer that they’re currently building is not suitable to break encryption. Although their adiabatic approach can be extended to be computationally equivalent to the gate-model approach, this seems to be not planned at the moment.

]]> By: Matt Ball http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-103865 Matt Ball Tue, 13 Nov 2007 21:21:53 +0000 http://toshuo.com/2007/d-waves-quantum-computers-are-the-real-deal/#comment-103865 Well since you put my name in the 'Tags', I've got to at least say something! So here we go... Last I had heard, it was unclear whether quantum computers can easily scale. There's a problem with keeping the qubits stable for the duration of the calculation. As you add more qubits, the problem gets worse. The other thing I heard was that you need A LOT of qubits to solve meaningful cryptographic problems. I believe that even with 500 qubits, a cluster of computers (for a fraction of the cost) can still out-perform the quantum computer for its proficient calculations. As an investment option, I would be very hesitant to go with D-Wave, but if they are able to scale the qubits gracefully, the potential is very large. Maybe a 90% chance they go bust, but a 10% chance they give a decent return. In any case, it's cool technology to follow, and I'm happy to see it get funding. Well since you put my name in the ‘Tags’, I’ve got to at least say something! So here we go…

Last I had heard, it was unclear whether quantum computers can easily scale. There’s a problem with keeping the qubits stable for the duration of the calculation. As you add more qubits, the problem gets worse.

The other thing I heard was that you need A LOT of qubits to solve meaningful cryptographic problems. I believe that even with 500 qubits, a cluster of computers (for a fraction of the cost) can still out-perform the quantum computer for its proficient calculations.

As an investment option, I would be very hesitant to go with D-Wave, but if they are able to scale the qubits gracefully, the potential is very large. Maybe a 90% chance they go bust, but a 10% chance they give a decent return. In any case, it’s cool technology to follow, and I’m happy to see it get funding.

]]>